In Focus - Radish

A fast growing root vegetable, often ready to harvest as early as 6 weeks, in the Brassicaceae (Previously Cruciferae) family in the order of Brassicales. Close family members are Broccoli, Mustard, Cabbage, Kale, Cauliflower and alyssum. With cousins being nasturtium, Papaya and Moringa.

Best grown in the cooler months in the Redlands, planting seeds early March through to late October.  Avoid planting in the hot summer months, as they tend to bolt. They can be grown in ground or using container methods, indoors or outdoors.  They need around 20cm of soil, loose and well draining soil (but not dry). Full sun 6+ hours in the cooler months. And they can tolerate dappled shade and do well as companion plants.

Radish comes in many varieties and colours, from a bright cherry red, to white and even green outside and pink middle (watermelon)

Radish likes to grow in 10-25*C in days consistently hotter then 28*C the radish likes to bolt and go to seed.  This is great though as radish flowers are sweet and tasty, so are the smaller green seed pods. Crunchy and sweet like a snap pea but with some radish heat. All varieties will produce seeds in varied amounts, though they need time to develop a strong root for a few months before flowering to be able to wow you with an absolute abundance of flowers. These flowers are loved by all nectar feeding insects, and radish flowers make great additions to summer salads.

 Growing

Radish likes a neutral carbon rich soil, 6-7pH and they tend not to bond with the native mycorrhizal networks but they really benefit from the bacterial microbes in the soil.  So a dose of fresh active home compost or worm castings before planting the seed is super beneficial.  Just a small handful of compost per seed is sufficient. Water in and keep the soil as consistently moist as possible, avoiding over watering.  A tender radish is one that has had an even amount of moister available over the growth period.

Seeds need to be placed no deeper then 1cm, you can multi sow 3-5 seeds per hole, or scatter them around, no closer then 15-25cm.  if they are to thickly planted you risk overlapping to many leaves and the radish reducing the amount of photosynthesis it can do, which reduces the amount of plant sugars, creating a more bitter radish. Seeds typically are quick to germinate and can come up as early as 3-7 days.

Germination 3-7 days (sprouts)

Leaf growth 1-2 weeks (microgreens)

Harvest 3-6 weeks (baby radish & greens)

Harvest 6-10 weeks (radish & young greens)

Flowering 20+ weeks (flowers and seed pods)

Per 100g of Radish

16 calories

Water 95.3g

Protein 0.6-0.8g

Fiber 1.6-1.9g

Carbs 3.4-3.9g (Sugar making up 2.2g)

Fat <0.1g

Sodium 0.047g (1% daily needs)

Vit C 0.0148g (14% of daily necessary intake)

Calcium, Folate, Potassium, Magnesium

Radish greens

Vit C, Vit A, Vit K, Vit B6, calcium, Iron, Magnesium, phosphorus, Potassium, Folic Acid

Radishes make great companion plants for most vegetables and fruits, as they are harvested quite quickly they can be interplanted with other seedlings when young, and they are out by the time the other crops need more sunshine.  They also make a good cover crop or filler crop for vacant spaces while you are waiting to plant other things. Large varieties like daikon, summer or tillage radish help to break up harder soils or create narrow channels down through the soil structure that carbons can be placed in without much effort on our end.  Letting the plant do the work.

Also with tillage radish you an just break off the greens, drop them on the ground over the top and leave the root to rot in place. Which will feed millions of soil microbes. Ducks and chickens also love to eat radish greens, and the tillage radish roots when young. Guinea pigs can also eat the root and leaves as long as they have no more then 10% total mixed vegetables (4-5 plant families) in a day and rotate them around so your Guinea pigs gets a variety of fun snacks

Seed Saving

When selecting your radish to collect seeds from in future pick your best radish, you will be super tempted to eat this amazing radish, but don’t as it will go on to provide excellent genes for the next generation. Also double check your leaf brix you will want the highest one to be the one you work at keeping for seeds too. Just keep up the consistent moisture and the occasional addition of compost, eat no more then half the flowers, or half the seed pods.  Just to make sure you have enough seeds for replanting next year. Let them stay on the plant until all the stems are dry (protect from heavy rain a few days before harvesting) then, roll the pods between your hands, or split the pods to remove the seeds. Store the dry seeds in paper envelops in a cool dry place. Seeds have the best viability in the first year and loose some viability each year, until eventually they will not have energy to sprout.

Available varieties

Pink/red

Champion

Cherry bell

China rose

Fire candle

French breakfast

Daikon red

Pink celebration

Crimson giant

sparkler

Yellow

Golden

Zlata Yellow

White

Daikon

Hailstone

Long white (summer)

Minowase

Mino early long

White beauty

White icicle

Black

Black Spanish long

Black Spanish round

Mixed

Confetti mix

Easter egg

watermelon

Purple

Plum purple

Flowers and pods

Rat tailed radish (best for pods)

Flowers can be pink to white across all varieties.

Common issues

Woody/hollow/bitter – uneven watering and not enough water, can also be cause by low/high pH symptoms such as unavailable hydrogen, calcium and potassium in the soil, can be from heavy soils and sandy soils lacking in carbon and microbial content, also likely to be a low leaf brix.  Work on regular moisture checks and water if on the drier side. Increase microbes by feeding them carbon, decomposing leaves or wood chips and fish emulsion are great sources of carbon. If needed add a bio stimulant/inoculant, if the pH is low you can also add some table sugar or black strap molasses to the water to feed the microbes.

No blubs, can be due to the previous, but mostly lack of sunlight, causes can be over crowding with other radishes or other plants. Heavy clay soil, compacted soil and soil psi over 200 in the first 20cm, loosen soil with broad fork and incorporate organics, and high carbon materials into the soil to help loosen the structure. To much nitrogen, excess nitrogen (and not enough carbon) in the soil lead to the plant trying to expel the excess nitrogen inti the leaves, and it will not be able to photosynthesize enough to create much sugar to store and build the bulb.  to hot at planting, the plant will force flower production.

Aphids, caterpillars, flea beetles – low brix, plain and simple.  Do your best to try and give those insects diabetes.  They have no pancreases so they can not process the high sugar levels of a healthy plant.  Increase brix by increasing microbes and soil diversity

Bolting to seed – stress and warm temperatures, this triggers the plant into pushing the next generation.